[text-decor-3][css-pseudo-4] Does text-emphasis apply to ::first-line or ::first-letter?

[fantasai]

The only mention of ::first-line and ::first-letter in css-text-decor-3 was in the definition of text-shadow. Selectors L3 also defines that text-decoration applies, so it's reasonable to assume that the rest of the line-decoration properties also apply... and css-pseudo-4 clarifies this point by incorporating by reference all of css-text-decor-3. And we assume in #2998 that text-emphasis-position at least applies to ::first-letter.

Should the rest of the text-emphasis properties also apply to ::first-line? What about ::first-letter? It seems fairly reasonable, since they inherit and then apply to text, similar to letter-spacing or color. But Firefox, which supports text-emphasis, does not apply it to these pseudo-elements, so I'm not sure if it's a problem to do so or not.

[fantasai]

WebKit implements this, and it's already specced, so closing out.